Relation between the Growth of Young Stand of Catalpa bungei and the Site Conditions of Low Mountain and Hilly Region

On the low mountain and hilly region in South Henan,qualitative and quantitative analysis on eleven factors which affect the growth of 2~4 years-old young stand of Catalpa bungti C.A.Mey have been conducted.The results show that the correlation between the growth of the young stand and the site condition is extremely significant.The factors affecting the tree height are arranged in following order: topographysoil depthsoil permeabilityslope exposuresoil fertilitysoil textureslope localityparent rockslopesunshine conditiongravel content.The factors affecting the D.B.H.are arranged in following order: topographysoil depthsoil fertilitysunshine conditionslope exposuresoil permeabilityslope locality soil textureparent rockgravel contentslope.Among these factors,topography and soil depth are the most significant factors to the growth.We obtain the multivariate line regression equations for the tree height and D.B.H.to the eleven site factors and the major factors,and work out the forecasting table for the young stand growth.